PC archeology: Laser XT Turbo "Leaking VARTA Battery" Edition
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- Опубликовано: 5 сен 2024
- Time to look at another old and neglected computer. This time it's a Laser XT Turbo clone. What mysteries and damage will this machine have?
Update: The board works! Thanks to several viewers, it seems this system needs a jumper to "disable" the keyboard lock. (In other words, you have to install the jumper to unlock the keyboard.) This is reverse of all other systems I have seen. It is working with a normal XT keyboard. Pictures: imgur.com/a/Rb...
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Laser XT Turbo manual:
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--- Instructional videos
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--- Music
Intro music and other tracks by:
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Thanks to several viewers who commented, turns out the Laser XT Turbo has a keyboard lock function which requires two pins to be SHORTED to enable (unlock) the keyboard. This is the reverse of all other motherboards I've come across. After figuring out the key lock pins, I installed a jumper and not a XT keyboard is working perfectly. System appears to work flawlessly as well. Control 5 and Control 8 change between regular normal speed and 2x "Turbo" speed. imgur.com/a/Rb1YFrQ
I could be wrong, but I was always taught XT, AT, and PS2 peripherals aren't hot pluggable (30 plus years ago ha!). I'm not saying it won't work, but plug and play was not a thing. There is some small risk of damage, and some devices just won't initialize properly. Regardless, it's your stuff, but for the young gamers best to treat these things delicately.
great news.awesome
The first thought I had when the keyboard didn't work was the lock, and I'm not at all familiar with Laser machines! Guess my troubleshooting skills are just on point 😅
@@tiporari Yup, XT/AT/PS2 is most DEFINTELY not safe to hotplug. You'll get away with it most of the time, but in my experience if you do it enough it WILL blow up the port eventually.
USB was pretty much the first PC connector that was to hot-plug and that was because it was specifically designed for that, note how the ground connector on the USB connector is sligtly longer so ground connects first. The next connector to be designed for hot-plugging was the SATA connectors (both data and power), again we see that they've made sure ground always connects first.
and you were showing off the keyboard lock in the beginning of the video !!! Nice video tho happens to the best of us!. thanks ! Joe
Adrian: "Hopefully this one is not so long"
Me: "uhuh"
Kind of funny that the PC that literally has “Turbo” in its name uses “High Speed Mode” label for a switch that pretty much everyone else was calling “Turbo” 🙂
Haha!! It's so true
"Hopefully this one is not so long..."
Well, that makes one of you. :)
Phosphoric acid (aka E338) isn't itself toxic - you find it in soft drinks quite a bit to give them some "bite" - but like any edible acid (including citric acid, malic acid, acetic acid, &c.), you don't necessarily want to drink it in anything but low concentrations!
Iirc, malic acid is safe in high concentrations, you can buy crystals of it in similar size to salt in grinders, the only side effect it has is causing your tongue to bleed, which isn’t fatal
Phosphoric acid is the sour taste in Coca-Cola, and I can't stand it, so when he said "toxic" I just went with it. (Remember the urban legend about cleaning your battery terminals with Coke? This is why. It kinda sorta works.) It's also used in making cheese.
@@sonicunleashedfan124 Is that the stuff on things like Sour Warheads? Because those always irritated the hell out of my tongue....lol.
@@VenomStryker yes
Keith Gaughan, re Phosphoric acid,
Or rub your eye when you are working with it.
THIS was my first computer, the holy grail if I can ever find one again (Along with the Magnavox RGB monitor from the Sears ad)
For the HDD, when the MFM/RLL drives start having issues booting it's always best to use the controller bios low level format routine to rewrite the track information. Then run spinrite/scandisk on it to check/fix/remap any bad sectors after. It was standard procedure back then to do that when pairing up drives to controllers. Also the ST225(R) sometimes had stiction issues and were fine once you got them spinning. The R in the ST225 model name meant that it was a certified RLL compatable drive, but it could also be re low level formatted to MFM. The opposite is also possible, but with mixed results depending on the quality of the platters. If you have a marginal RLL drive it may be a perfectly fine MFM drive when re-lowleved (with reduced space).
To be honest, the ST-225R label puzzles me. IIRC, the RLL version of the famous ST-225 was labelled ST-238R (denoting the capacity of a 25meg MFM drive formatted to 38meg RLL). But it seams, they just tucked a "R" behind the name to indicate RLL-formatting capability. Suffice to say, that when RLL controllers appeared, everybody just tried to reformat their MFM drive to RLL to gain the speed and capacity. Most of the time, it just worked fine.
@@virtualinfinity6280 Back then it was quite common to low-level format the MFM drives to try and get more space. Most of the time it was fine, but some drives didn't take it well, not good enough media for the data density. Yeah the drive labels were a bit of a mess back then, Miniscribe had some archane numbering too for their drives. All of them were noisy (Micropolis and Miniscribe especially).
@@virtualinfinity6280 The 225R was something like 17 MB "naked" when MFM was used, so 14 MB or so after partitioning and formatting. Nobody wanted a 14 MB drive in 1989, which means this design simply wasn't marketable without the RLL space bonus. Since the people with pocket change had moved on to the ST-251 by then, or something even larger, nobody really cared whether their 20 MB drive was a small drive being pushed by the controller, or a sloppy bigger old one not being pushed. Fortunately for Seagate, the ST-225R was fairly reliable (comparable to the 225 and 251).
If you took an ST-225 and stuck it on an RLL controller (I do specifically mean the common 2,7 RLL of the day, not the even higher density variants that appear inside IDE drives) you got an ST-238R. The only difference between an ST-225 and an ST-238R is that if your ST-238R didn't work with an RLL controller, you could return it as defective but if your ST-225 didn't want to (but worked on the MFM controller) you were SOL because "running RLL" was not guaranteed. In practice, it almost always worked just fine. Also all the 238R models were the faster of the two variants of the 225, because the slower-seeking one became obnoxiously noticeable when dealing with 26-sector tracks.
Oxidation requires air, so sealing traces after cleaning them with laquer should preserve a fix.
If the 3.5" floppy is HD the original controller won't take it, it ends up on 720k floppies.
Yes. Try it with the 5.25" floppy, Adrian!
I had an XT machine way back where the keyboard lock pins had to be shorted if the mainboard was not in the case otherwise the keyboard didn't work, maybe this is the issue
I checked the manual and section 2.12 says the pins do need to be shorted for the keyboard to work
Thank you for the tip Motolav and Rob!!! I will do a quick follow-up test. Awesome!
Yep that was it! Motherboard is booting and working fine. imgur.com/a/Rb1YFrQ
@@adriansdigitalbasement2 Glad we could help! Thanks for the great content
@@adriansdigitalbasement2 from what i could tell is that the Laser XT/3 motherboard is almost the same design.. (i have this machine here) and restored it almost.
Its weird to see that the installation of the ram chips (conventional memory) is on the other side on the motherboard 8088 XT vs 8086 XT/3
Here the installation of the dip memory starts on the upper side where the DMA controller IC is. Then the two banks on the left are for 512KB. And the sockets underneath is (which you showing us in the video) are for install the 128KB of memory.. The 2 rows on the right side is for EMS memory installation.
I have upgrade my system with new memory chips, had to soldered in a new IC socket for the DMA IC and also replaced that due corrosion.
Added an Intel 8087-1 10 Mhz co-processor *just because* Upgraded my NEC 20MB MFM drive for a Seagate ST-277R 65MB
added and EAGLE II graphics card. ADDed HD_floppy controller. Replaced the old 720KB drive with an 1.44MB one (because those diskettes are more available) (but still the 360Kb chinon drive 5,25 is original. Further will add, an SB 1.5 to it, ethernet card from SMC 3008TP, and adapter ACB-2070 RLL controller.
Also will add an Roland MPU-ICT to it, for connecting an MT32 to it.
What i do to revive old Winchester or other hard drives. Connect them only to the power supply (without interface cables) And let it warm up for some time.
Also try to lubricate the spindle bearing if it is possible with that teflon grease (tri flow) If its sound good again.. Try to see whats on the drive, if you know on which controller it was installed on. Then backup the data you need. If its done, re low level format it and start over.. Due age, the magnetic surface gets more errors and data loss. To reformat it you will prefend that.
Using RLL (1,7) encoding gave roughly 50% extra capacity over MFM for nothing, but required very precise control over the spindle speed to provide accurate timing. You can put any MFM drive onto an RLL controller and low level format it to RLL, but if the spindle speed is not constant it will be unreliable or unreadable. A RLL drive suffering with bad bearings or motors would also cause issues with the encoding and produce errors. Changing the controller card can also cause issues if the drive is not low level formatted on the new controller.
Some manufacturers would only certify certain drives for RLL like the (R) one you have. Some top end disk suppliers would build drives to RLL spec regardless and sell them as MFM or RLL drives regardless.
lol not long only 1 hour but 1 hour of fun
Hahaha
Same as with the not so mini mail calls 😅 But we always like more!
Me: Yay new video from Adrian! I hope it’s a long one.
Adrian: Hopefully it’s not going to be so long!
Me: Yay it’s a long boi 🥳
"This... is... VARTA !!"
"I have become Varta, destroyer of motherboards."
Hopefully this one is not so long... 51 minutes later :) ... actually thanks Adrian! :)
Just an aside - I was warned to never plug an AT or XT keyboard into the connector while the board was powered up. Damage to both could occur. That may be incorrect, but I do remember it.
Agreed! They are not "hot swappable".
The ST-225R actually has the same 21 MB capacity as the regular ST-225, but the higher density of the RLL encoding allows it to use only one platter instead of two, making it a lower-cost and less power-hungry drive.
It also means you can't squeeze an extra 50% space out of it by swapping out the controller for an RLL controller, something we often did with non-R ST-225s when they were no longer desirable (most everyone having moved to the ST-251, which RLLs to a ST-277R). Ah well, Seagate was under no obligation to enable our hacks.
I bought a Laser XT Turbo new in 1985 and another working spare unit (for parts) in 1999. It still boots and works fine, as does the spare.
Reads label "do not put on aluminum." Immediately puts it on electrolytic capacitors which have an aluminum shell. ^-^
Adrain, I am staring to like you second channel better than the first, but I still watch them both!
Hello, Adrian! You've actually been testing this floppy/serial controller card with another disk drive and diskette, than you booted previously. So it may be still working 🙂
Wow - Form Tool! I used that program a lot many moons ago. Once you got used to its controls (just like with Word) it was a very useful program. Created many equipment checklists and such with it. Thank you for the trip down memory lane. Regards, David
Being a loyal C= boy, I don't have much nostalgy for crusty old PCs, but Adrian makes them interesting. Nice one Sir!
When this XT was around, i was using the C64, when the 286 was around i was still using the C64, when the 386 was around i was using the Amiga, when the 486 was around i was STILL using the Amiga. Then i got a PC.
Damn, just set up my VR for a long time, but as I saw a new retro video from Adrian, I guess the VR can wait.
Historical note - the bank-switched memory was called "expanded memory", which was a standard developed jointly by Lotus, Intel, and Microsoft (LIM). It was a nightmare to program and even to set up. "Extended memory" (XMS) came with the 286 and its larger address space and was usable by anything that supplied a proper memory manager. The old Netware operating system would bootstrap in DOS and then immediately load its own extended memory manager. Windows 3 and OS/2 could use this memory directly.
RLL encoding (AKA relative run length) was a way to get more storage from the same area of magnetic surface over MFM (modified frequency modulation). This was a HUGE gain back in the day, because an RLL drive cost about the same as an MFM drive, but you got more storage space. A very economical tech advancement.
You have to realize that magnetic hard drives were very young back then, and we're the beneficiaries of a long chain of very expensive research to get to the rotating magnetic media we have now.
Of course everything is going flash memory now (SSD's are flash based). Good luck finding a working SSD from today being readable or usable 40 years from now... ^-^
* reading card * "Things you can say during a date *or* during a ADB episode."
* buzzer * "I just wanna see if the old thing works."
*buzzer* "Would you look at that! It works!!"
"Hopefully this one is not so long..."
"It's looking a little bit crusty and green."
VARTA: a 4 letter word in the retro computing community
You mean 5 letters? V-1 A-2 R-3 T-4 A-5
But yeah, those VARTA batteries are the bringers of doom and destruction on any computer that hosts those pieces of shit.
The Q in VARTA stands for quality.
@@nekomasteryoutube3232 "four letter word" means a swear word
Actually, choosing those batteries was a sign of quality-conciousness. Believe it or not - they where top-quality back then. I think it's fairly safe to assume, that someone soldering a battery to a PCB and not even considering a proper battery socket never anticipated the product to be "in use" after 40 years or so :)
@@virtualinfinity6280 True dat. Show me any battery that did not fail after ten times it´s planned lifetime. Without proper charge / discharge cycles. It´s like people complaining that the fuel and battery in a 40 year old barn-find Chevy Corvette do not work anymore and are causing corrosion issues :)
"so hopefully this video won't be as long..." - releases 52 minute video (-:
I’ve configured lots of these Laser Turbo XT and later machines when I started my first job in the early 90’s at a ////Laser dealer in Belgium. Solid and affordable machines for the time. We also sold Compaq machines. Can’t remember if these XT machines used a special keyboard… Don’t think so, but there was a keyboard lock I believe. The Seagate RLL drives were a frequent point of failure. Thank you for making these videos!
I left the computer on last night and woke up to Adrian's Digital Basement.
I dunno, watching Adrian paint that goopy acid was nearly as enjoyable as a good Bob Ross
I feel like a large ulrasonic cleaner would be good here, with vinegar then a distilled water wash
If a motor has permanent magnets in it then it is not an induction motor. It is a permanent magnet synchronous motor if was driven by sinus, or BLDC if was driven by square wave.
PC Write got a lot of use in our house! PCW was the Personal Computer World magazine which came with a 5 1/4 inch floppy mainly with shareware here (at least) in the UK
LOL your memory is perfect regarding the hard drive controller, right down to you remembering g=c800:5. You probably also remember it lets you enter the bad cylinders as well. :)
Please dont connect or disconnect the keyboard when the PC is on, you can easily kill things that way
I second this! I have killed multiple key oard controllers this way. XT/AT/PS/2 keyboards are NOT hot swappable like USB
I nearly killed a computer and monitor when unplugging it while it was on. Those were harsh times
No problem with a long video from Adrian. You can allways listen to it at 1,5x speed. :)
Fun fact: the same phosphoric acid that’s the active ingredient in Naval Jelly is also used in many carbonated beverages (and the old time ‘phosphate’ sodas) to give that ‘sour’ taste.
Albeit at a much lower concentration! (The soda ingredient is called “acid phosphate” and it’s more dilute, and has a couple extra components in it)
Have you ever done the run it through the dishwasher routine on boards like this or worse? Contrary to myth, there are no particulates in dishwasher detergent to sandpaper anything. I've never tried it but have done a thorough washing in regular water (hard water here in San Diego), lots of dish soap, and various brushes, toothbrush, etc. on a motherboard (486 as I recall) that had gotten rusty(?) from living near the ocean here and didn't work/boot at all. I'd removed all socketed chips first. When done, I blew it out thoroughly (especially under surface mount chips) with my air compressor (yes, I know, risk of static), then rinsed thoroughly again with 90% rubbing alcohol (best I could find), then blew it out again. Finally leaving it out in our San Diego sunshine for a day. Put everything back together and lo and behold, it booted right up and ran for years! Not sure what happened to it eventually, though, may have failed again but as mentioned, it ran flawlessly for many (5+) years. 'twas an experiment in the washing idea, and had nothing to lose and gained a nice system.
Ooohh jackpot on the ST11R RLL card with the 225R. I have a 238R, But only an MFM controller for it. Those RLL cards are harder to find than the MFM cards are.
34:20 Adrian, FYI you can hold shift during DOS boot to skip autoexec/config sys.
The speaker mount is kinda cool. Oh and I also love the DOS font!
The ST-11M/R controller only works with a subset of drives which are programmed in its firmware. It will actually attempt to identify the drive using the data stored in the drive's onboard ROM. And one thing which is interesting about those controllers is that they are implemented with a mask programmed gate array and the controller microcode is stored on a separate ROM. The RLL version is one of the few controllers, according to the stason website, which supports drives with 31 sectors per track.
"Leaking VARTA battery edition".....HILARIOUS!
Love to see old lit being restored. Have you considered using the little interdental toothbrushes for getting into slot/chip socket crevices?
I love the Laser XT computers. I have several of the compact ones (the ones that look like Amigas with the disk plugging into the right side), but don't have any of these Turbo ones. Very cool system. I didn't know your parents were Mexican, you don't seem spanish.
For a while in the mid to late 1990'sI was able to buy used XTs from a local liquidation outfit for $5.00 each. Stripping one down yielded a case and PSU far superior to most available at the time, and a treasure trove of miscellaneous fastener hardware for reuse.
I would install various iterations of pentium or AMD mainboards and up to date HDDs in them. The power supplies were fully compatible and of much higher quality than that of the many smaller, cheaper, and cheesier PSUs that were flooding the market.
The trend at the time was toward vertically oriented tower and mini tower cases, but I preferred the looks and solid construction of the old IBM's. I wish I still had at least one around to play with.
Give this a try some time. I have used cornstarch to thicken vinegar for exactly what you have the naval jelly for. Just food for though? (ha)
Enjoyed the Bob Ross cameo at around 16 mins
keyboard may be locked...
Good old Varta...
VARTA, DESTROYER OF BOARDS
I noticed the battery eaten controller was tested with a HD floppy drive and disk. If I recall older controllers only supported 360k or 720k. I think you need an upgraded chipset for 1.44? Maybe test with the 360k drive? Nice socketed z80 on that board.
Perhaps the composite color output on that CGA card depends on a color trimmer on the motherboard. I tried a CGA card on a 286 PC and it wouldn't output color composite because the motherboard is missing that component.
I tested it again later after this video and it dees actually work -- just only in 40 col and 320x240 modes -- which is actually a good choice because the 640 pixel modes (like 80 col) are unreadable in color modes.
@@adriansdigitalbasement2 That video card will support Hercules 720x348 monochrome graphics on the 9 pin connector. I had this model, and played "Prince Of Persia", and "Ken's Labyrinth" in Hercules mode on an amber, and later a green phosphor screen before upgrading to a Trident TVGA8900 512KB VGA card and screen.
The first computer I ever used :) so hard to find but so cool looking!
I heard you are visiting Mexico in October? Cool! Where are you going? Beach? City? Greetings from a Mexican long-time viewer!
Still planning on it! Every year I go with friends to Puerto Vallarta and stay down in the Zona Romántica.
I almost wonder if the RCA outputs on that CGA card are split into Luma and Chroma. It probably isn't, but if it is, you can probably turn it into regular composite by coupling to the second one's output with a 470pF capacitor - you'd want the Luma output going straight to your monitor (or converter) and a 470pF between the Chroma output and the wire carrying Luma. This wouldn't be perfect, but in such configurations it will usually get you at least some color. Alternately, you could just make up a cable to connect them directly to an S-Video input on something if they are indeed split Luma/Chroma.
Thanks Adrian! I am going to try the Naval Jelly on the worst spots of the Amiga 3000 I am going to restore soon. The battery damage is pretty significant but I HAVE to get it going! 😎
That might not be enough for an Amiga 3000... they're notorious for eating vias. The legend himself John Hertell has been doing amazing work on his ReAmiga 3000 PCB though so it can be saved either way. www.reamiga.info/?page_id=40
@@Carcenomy Thanks, I had heard of it but now its bookmarked! I am hoping to save the original board. My buddy from back in the day gave it to me recently and we used it to design our users group newsletter. Its not my original Amiga but it is one I worked on and used back then!
@@RavenWolfRetroTech I wouldn't feel bad if reboarding it becomes the option, you can make some massive quality of life improvements like SIMMs instead of ZIPs that way. But keen to see it fixed, the 3000 is a pretty unique specimen!
EMS memory... TIE-fighter squadron checking in
XT class clone machines having proprietary keyboards was really common. Amstrad etc
Excellent. I love these videos.
I had one of those! That was my first PC! Laser Turbo XT! 40MB Seagate and all! It went into the landfill decades ago, the cpu had stuck bits.
The labeling on that hard drive is exactly how mine was too. Maybe some OEM thing they did. Holy shot this is a blast directly from my past.
And yeah there’s actually a full menu system in the C800 on that MFM card. I seem to remember you started that at a different offset in the segment than 5. But even with the basic interface you had basically full control of the low level format. I remember it because it was an at least yearly ordeal after the drive aged and became very sensitive to the ambient temperatures.
Red switch on the back is yes the reset.
The BIOS is picky about keyboards. Mine worked with the Laser and a model M but nothing else as I recall…any XT/AT keyboard made later gave a keyboard error or just locked the thing up.
My dad and I used PC-Write for years. It was a good word processor.
Pcwrite was a free/shareware word processor used often when I was in college from in the late 1980s.
60fps.... so smoooooooth!
So they are IKEA Longdrink glasses! Thought I recognised them.
Normally what I do with old drives is I copy the files to a floppy, run a low-level format, then copy the files back.
"Think of the Varta, Shad. What is the first law of the Varta?" Clip. The. Battery.
You can also replace them with new Vartas but I think everyone chooses the coin cell for obvious reasons.
The way I clean this type of corroded slots is using hand clean wipes. I let them out to dry for a day. I soaked them with vinegar then push them in the slot with a credit card. Leave them in for a few hours and it will absorb the corrosion, they'll turn blue. Repeat the process several times and end up cleaning the rest of the corrosion with a tooth brush and vinegar.
That's a good strategy!
Having DOS installed onto the root of the drive like that is not surprising. If you look at the installation instructions (based on the IBM PC-DOS 3.30 manual) it tells you to enter SELECT C: 44 UK (well, the last two are location specific but you get the idea). What a sane person would do is replace C: with C:\DOS but the manual doesn't tell you that so on the first attempt you get a root level full of files and slightly annoyed at whoever wrote the docs.
Some old connector ports can get broken by hotplugging stuff. I think at least PS/2 was prone to breaking something on hotplug.
You should be able to protect your de-rusted parts by coating them with some paint to keep out moist air. Even a coat of oil or wax should be sufficient.
is the Floppy Controller Bad or is there a problem with 1.44Meg Support? Did you tested the Controller wilth the 5,25 Drive?
"Vinegar is difficult to get into the isa slots. " .. umm Adrian, it's easier than trying to force a thick gel inside. Get some toilet paper and place it down where you want to pour the vinegar and that keeps the vinegar in place and its a lot cheaper. That stuff you use, this "naval gel" is £20 a tub in the UK!. Oh just pour the vinegar into the isa slots and leave it. Or sprinkle baking soda on the green then drip the vinegar on. Simple and much much cheaper. By the way where did you get that micro TV with the 80s style animation running?
Ahhhh Expanded Memory. Those were the days.
and we don't miss them
My first XT had a 30mb RLL hard disk. Remember those?
Either that PC was stored vertically on it's rear, or that battery EXPLODED
You probably need a model F keyboard, not a model M. (function keys in two columns on the left)
28:46 Afterthought indeed. I used to buy push buttons like that from Radio Shack in a five pack.
Phrasing!
If the video card has a true monochrome mode, that uses a different screen mode for text. Hot swapping connections would not automatically change the screen mode. I don't recall if BASIC allowed you to switch, but if you don't have a tool kit to change the video mode I think it is a call to INT 10H. It was easy to do with debug. ah=0, al=mode
Oh Dissolvente de Oxido, nice label in Portuguese. Hahaa and nice video
12:00 I searched for months for a power supply like that to build a laboratory power supply with that beautiful shiny case. I did not get it
I believe I have the original schematics for one of these or an original laser xt. Bought them from someone who used to sell these
Very unusual to see power-supply survived that long.
Hey, Adrian,
I wouldn't worry about that green ISA slot... I have fixed worse stuff than that :)
I saw a Zilog chip on the controller card. Maybe a Z80?
27:11 i would try different compatible functioning keyboard, if it would act the same, i would say it's keyb.controller on the mobo
As a friend of mine once said... "I'm going to format the hard drive with coarse sand paper and install Pac-Man!"
In their defence, Varta do make pretty reliable car batteries. Admittedly a bit bulky for this application though…
8:41 I’m not sure he is the original for the “enhance” or not, but I wouldn’t figure you are a South Main Auto viewer. I got a giggle out of it anyway
I wouldn't be surprised if that Chinon 5 1/4 inch drive is actually HD. After all, it was made in '89. I have a few of those and they're all HD (although mine are all... what would you call that, dark beige? What Commodore used on some of their cases - some of them even came in Commodore PCs - and they're definitely HD drives)
Some, not all - Commodore used those Chinons in virtually everything with a 5.25" drive at one time or another! But in the XT class stuff (I've had like four PC10-IIIs) they were all 360K.
Is that the same V-Tech that makes those Leapfrog computers?
The fact the hard drive is struggling to boot but it's still readable after boot might just be a spin up time thing?
any review of your magnify glasses you have.. i need one for electronics but i have mixed reviews ones say they are crap others says is fine.
16:19 It looks like some of the bottle's contents might be dripping down the side, fyi.
You might consider dumping the BIOS chips from the non-working cards. I would imagine that those would be hard to get. Maybe upload the images to the way-back machine for posterity?
you should try cleaning vinegar. it is twice as strong and i have had good results cleaning better leakage.
Going by that software, there's a chance that that PC belonged to a bank.
i have a 1990 dated Hyundai Super16TE 8088 XT machine, has similar nicad damage 😢
i washed mine with 'diluted' liquid phosphoric acid rust killer, similar as you had in the video, but not jelly type , scrubbed it with an old toothbrush, also had a tiny bit of washing up liquid mixed with it, it soon killed the corrosion, many say use vinegar but i cant stand the stench of the stuff ... theres some completely rotted tracks, i've started patching them but left it for now to do other stuff
Why does your power supply have a 5 1/4" floppy taped to it? Trying to degauss it over a LONG period of time?